[linux-2.6-block.git] / fs / xfs / xfs_utils.c

/*
 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_error.h"
#include "xfs_quota.h"
#include "xfs_rw.h"
#include "xfs_itable.h"
#include "xfs_utils.h"


/*
 * Allocates a new inode from disk and return a pointer to the
 * incore copy. This routine will internally commit the current
 * transaction and allocate a new one if the Space Manager needed
 * to do an allocation to replenish the inode free-list.
 *
 * This routine is designed to be called from xfs_create and
 * xfs_create_dir.
 *
 */
int
xfs_dir_ialloc(
	xfs_trans_t	**tpp,		/* input: current transaction;
					   output: may be a new transaction. */
	xfs_inode_t	*dp,		/* directory within whose allocate
					   the inode. */
	mode_t		mode,
	xfs_nlink_t	nlink,
	xfs_dev_t	rdev,
	cred_t		*credp,
	prid_t		prid,		/* project id */
	int		okalloc,	/* ok to allocate new space */
	xfs_inode_t	**ipp,		/* pointer to inode; it will be
					   locked. */
	int		*committed)

{
	xfs_trans_t	*tp;
	xfs_trans_t	*ntp;
	xfs_inode_t	*ip;
	xfs_buf_t	*ialloc_context = NULL;
	boolean_t	call_again = B_FALSE;
	int		code;
	uint		log_res;
	uint		log_count;
	void		*dqinfo;
	uint		tflags;

	tp = *tpp;
	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);

	/*
	 * xfs_ialloc will return a pointer to an incore inode if
	 * the Space Manager has an available inode on the free
	 * list. Otherwise, it will do an allocation and replenish
	 * the freelist.  Since we can only do one allocation per
	 * transaction without deadlocks, we will need to commit the
	 * current transaction and start a new one.  We will then
	 * need to call xfs_ialloc again to get the inode.
	 *
	 * If xfs_ialloc did an allocation to replenish the freelist,
	 * it returns the bp containing the head of the freelist as
	 * ialloc_context. We will hold a lock on it across the
	 * transaction commit so that no other process can steal
	 * the inode(s) that we've just allocated.
	 */
	code = xfs_ialloc(tp, dp, mode, nlink, rdev, credp, prid, okalloc,
			  &ialloc_context, &call_again, &ip);

	/*
	 * Return an error if we were unable to allocate a new inode.
	 * This should only happen if we run out of space on disk or
	 * encounter a disk error.
	 */
	if (code) {
		*ipp = NULL;
		return code;
	}
	if (!call_again && (ip == NULL)) {
		*ipp = NULL;
		return XFS_ERROR(ENOSPC);
	}

	/*
	 * If call_again is set, then we were unable to get an
	 * inode in one operation.  We need to commit the current
	 * transaction and call xfs_ialloc() again.  It is guaranteed
	 * to succeed the second time.
	 */
	if (call_again) {

		/*
		 * Normally, xfs_trans_commit releases all the locks.
		 * We call bhold to hang on to the ialloc_context across
		 * the commit.  Holding this buffer prevents any other
		 * processes from doing any allocations in this
		 * allocation group.
		 */
		xfs_trans_bhold(tp, ialloc_context);
		/*
		 * Save the log reservation so we can use
		 * them in the next transaction.
		 */
		log_res = xfs_trans_get_log_res(tp);
		log_count = xfs_trans_get_log_count(tp);

		/*
		 * We want the quota changes to be associated with the next
		 * transaction, NOT this one. So, detach the dqinfo from this
		 * and attach it to the next transaction.
		 */
		dqinfo = NULL;
		tflags = 0;
		if (tp->t_dqinfo) {
			dqinfo = (void *)tp->t_dqinfo;
			tp->t_dqinfo = NULL;
			tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
			tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
		}

		ntp = xfs_trans_dup(tp);
		code = xfs_trans_commit(tp, 0);
		tp = ntp;
		if (committed != NULL) {
			*committed = 1;
		}
		/*
		 * If we get an error during the commit processing,
		 * release the buffer that is still held and return
		 * to the caller.
		 */
		if (code) {
			xfs_buf_relse(ialloc_context);
			if (dqinfo) {
				tp->t_dqinfo = dqinfo;
				xfs_trans_free_dqinfo(tp);
			}
			*tpp = ntp;
			*ipp = NULL;
			return code;
		}

		/*
		 * transaction commit worked ok so we can drop the extra ticket
		 * reference that we gained in xfs_trans_dup()
		 */
		xfs_log_ticket_put(tp->t_ticket);
		code = xfs_trans_reserve(tp, 0, log_res, 0,
					 XFS_TRANS_PERM_LOG_RES, log_count);
		/*
		 * Re-attach the quota info that we detached from prev trx.
		 */
		if (dqinfo) {
			tp->t_dqinfo = dqinfo;
			tp->t_flags |= tflags;
		}

		if (code) {
			xfs_buf_relse(ialloc_context);
			*tpp = ntp;
			*ipp = NULL;
			return code;
		}
		xfs_trans_bjoin(tp, ialloc_context);

		/*
		 * Call ialloc again. Since we've locked out all
		 * other allocations in this allocation group,
		 * this call should always succeed.
		 */
		code = xfs_ialloc(tp, dp, mode, nlink, rdev, credp, prid,
				  okalloc, &ialloc_context, &call_again, &ip);

		/*
		 * If we get an error at this point, return to the caller
		 * so that the current transaction can be aborted.
		 */
		if (code) {
			*tpp = tp;
			*ipp = NULL;
			return code;
		}
		ASSERT ((!call_again) && (ip != NULL));

	} else {
		if (committed != NULL) {
			*committed = 0;
		}
	}

	*ipp = ip;
	*tpp = tp;

	return 0;
}

/*
 * Decrement the link count on an inode & log the change.
 * If this causes the link count to go to zero, initiate the
 * logging activity required to truncate a file.
 */
int				/* error */
xfs_droplink(
	xfs_trans_t *tp,
	xfs_inode_t *ip)
{
	int	error;

	xfs_ichgtime(ip, XFS_ICHGTIME_CHG);

	ASSERT (ip->i_d.di_nlink > 0);
	ip->i_d.di_nlink--;
	drop_nlink(VFS_I(ip));
	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

	error = 0;
	if (ip->i_d.di_nlink == 0) {
		/*
		 * We're dropping the last link to this file.
		 * Move the on-disk inode to the AGI unlinked list.
		 * From xfs_inactive() we will pull the inode from
		 * the list and free it.
		 */
		error = xfs_iunlink(tp, ip);
	}
	return error;
}

/*
 * This gets called when the inode's version needs to be changed from 1 to 2.
 * Currently this happens when the nlink field overflows the old 16-bit value
 * or when chproj is called to change the project for the first time.
 * As a side effect the superblock version will also get rev'd
 * to contain the NLINK bit.
 */
void
xfs_bump_ino_vers2(
	xfs_trans_t	*tp,
	xfs_inode_t	*ip)
{
	xfs_mount_t	*mp;

	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
	ASSERT(ip->i_d.di_version == 1);

	ip->i_d.di_version = 2;
	ip->i_d.di_onlink = 0;
	memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
	mp = tp->t_mountp;
	if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
		spin_lock(&mp->m_sb_lock);
		if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
			xfs_sb_version_addnlink(&mp->m_sb);
			spin_unlock(&mp->m_sb_lock);
			xfs_mod_sb(tp, XFS_SB_VERSIONNUM);
		} else {
			spin_unlock(&mp->m_sb_lock);
		}
	}
	/* Caller must log the inode */
}

/*
 * Increment the link count on an inode & log the change.
 */
int
xfs_bumplink(
	xfs_trans_t *tp,
	xfs_inode_t *ip)
{
	if (ip->i_d.di_nlink >= XFS_MAXLINK)
		return XFS_ERROR(EMLINK);
	xfs_ichgtime(ip, XFS_ICHGTIME_CHG);

	ASSERT(ip->i_d.di_nlink > 0);
	ip->i_d.di_nlink++;
	inc_nlink(VFS_I(ip));
	if ((ip->i_d.di_version == 1) &&
	    (ip->i_d.di_nlink > XFS_MAXLINK_1)) {
		/*
		 * The inode has increased its number of links beyond
		 * what can fit in an old format inode.  It now needs
		 * to be converted to a version 2 inode with a 32 bit
		 * link count.  If this is the first inode in the file
		 * system to do this, then we need to bump the superblock
		 * version number as well.
		 */
		xfs_bump_ino_vers2(tp, ip);
	}

	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
	return 0;
}

/*
 * Try to truncate the given file to 0 length.  Currently called
 * only out of xfs_remove when it has to truncate a file to free
 * up space for the remove to proceed.
 */
int
xfs_truncate_file(
	xfs_mount_t	*mp,
	xfs_inode_t	*ip)
{
	xfs_trans_t	*tp;
	int		error;

#ifdef QUOTADEBUG
	/*
	 * This is called to truncate the quotainodes too.
	 */
	if (XFS_IS_UQUOTA_ON(mp)) {
		if (ip->i_ino != mp->m_sb.sb_uquotino)
			ASSERT(ip->i_udquot);
	}
	if (XFS_IS_OQUOTA_ON(mp)) {
		if (ip->i_ino != mp->m_sb.sb_gquotino)
			ASSERT(ip->i_gdquot);
	}
#endif
	/*
	 * Make the call to xfs_itruncate_start before starting the
	 * transaction, because we cannot make the call while we're
	 * in a transaction.
	 */
	xfs_ilock(ip, XFS_IOLOCK_EXCL);
	error = xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, (xfs_fsize_t)0);
	if (error) {
		xfs_iunlock(ip, XFS_IOLOCK_EXCL);
		return error;
	}

	tp = xfs_trans_alloc(mp, XFS_TRANS_TRUNCATE_FILE);
	if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
				      XFS_TRANS_PERM_LOG_RES,
				      XFS_ITRUNCATE_LOG_COUNT))) {
		xfs_trans_cancel(tp, 0);
		xfs_iunlock(ip, XFS_IOLOCK_EXCL);
		return error;
	}

	/*
	 * Follow the normal truncate locking protocol.  Since we
	 * hold the inode in the transaction, we know that its number
	 * of references will stay constant.
	 */
	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
	xfs_trans_ihold(tp, ip);
	/*
	 * Signal a sync xaction.  The only case where that isn't
	 * the case is if we're truncating an already unlinked file
	 * on a wsync fs.  In that case, we know the blocks can't
	 * reappear in the file because the links to file are
	 * permanently toast.  Currently, we're always going to
	 * want a sync transaction because this code is being
	 * called from places where nlink is guaranteed to be 1
	 * but I'm leaving the tests in to protect against future
	 * changes -- rcc.
	 */
	error = xfs_itruncate_finish(&tp, ip, (xfs_fsize_t)0,
				     XFS_DATA_FORK,
				     ((ip->i_d.di_nlink != 0 ||
				       !(mp->m_flags & XFS_MOUNT_WSYNC))
				      ? 1 : 0));
	if (error) {
		xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES |
				 XFS_TRANS_ABORT);
	} else {
		xfs_ichgtime(ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
		error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
	}
	xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);

	return error;
}
Commit	Line	Data
1da177e4	1	/*
7b718769 NS	2	* Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
7b718769 NS	3	* All Rights Reserved.
1da177e4	4	*
7b718769 NS	5	* This program is free software; you can redistribute it and/or
7b718769 NS	6	* modify it under the terms of the GNU General Public License as
1da177e4 LT	7	* published by the Free Software Foundation.
1da177e4 LT	8	*
7b718769 NS	9	* This program is distributed in the hope that it would be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
1da177e4	13	*
7b718769 NS	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write the Free Software Foundation,
	16	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
1da177e4	17	*/
1da177e4	18	#include "xfs.h"
a844f451	19	#include "xfs_fs.h"
1da177e4	20	#include "xfs_types.h"
a844f451	21	#include "xfs_bit.h"
1da177e4	22	#include "xfs_log.h"
a844f451	23	#include "xfs_inum.h"
1da177e4 LT	24	#include "xfs_trans.h"
1da177e4 LT	25	#include "xfs_sb.h"
a844f451	26	#include "xfs_ag.h"
1da177e4 LT	27	#include "xfs_dir2.h"
	28	#include "xfs_dmapi.h"
	29	#include "xfs_mount.h"
	30	#include "xfs_bmap_btree.h"
1da177e4	31	#include "xfs_dir2_sf.h"
a844f451	32	#include "xfs_attr_sf.h"
1da177e4	33	#include "xfs_dinode.h"
1da177e4	34	#include "xfs_inode.h"
a844f451	35	#include "xfs_inode_item.h"
1da177e4 LT	36	#include "xfs_bmap.h"
	37	#include "xfs_error.h"
	38	#include "xfs_quota.h"
	39	#include "xfs_rw.h"
	40	#include "xfs_itable.h"
	41	#include "xfs_utils.h"
	42
1da177e4	43
1da177e4 LT	44	/*
	45	* Allocates a new inode from disk and return a pointer to the
	46	* incore copy. This routine will internally commit the current
	47	* transaction and allocate a new one if the Space Manager needed
	48	* to do an allocation to replenish the inode free-list.
	49	*
	50	* This routine is designed to be called from xfs_create and
	51	* xfs_create_dir.
	52	*
	53	*/
	54	int
	55	xfs_dir_ialloc(
	56	xfs_trans_t *tpp, / input: current transaction;
	57	output: may be a new transaction. */
	58	xfs_inode_t dp, / directory within whose allocate
	59	the inode. */
	60	mode_t mode,
31b084ae	61	xfs_nlink_t nlink,
1da177e4 LT	62	xfs_dev_t rdev,
	63	cred_t *credp,
	64	prid_t prid, /* project id */
	65	int okalloc, /* ok to allocate new space */
	66	xfs_inode_t *ipp, / pointer to inode; it will be
	67	locked. */
	68	int *committed)
	69
	70	{
	71	xfs_trans_t *tp;
	72	xfs_trans_t *ntp;
	73	xfs_inode_t *ip;
	74	xfs_buf_t *ialloc_context = NULL;
	75	boolean_t call_again = B_FALSE;
	76	int code;
	77	uint log_res;
	78	uint log_count;
	79	void *dqinfo;
	80	uint tflags;
	81
	82	tp = *tpp;
	83	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
	84
	85	/*
	86	* xfs_ialloc will return a pointer to an incore inode if
	87	* the Space Manager has an available inode on the free
	88	* list. Otherwise, it will do an allocation and replenish
	89	* the freelist. Since we can only do one allocation per
	90	* transaction without deadlocks, we will need to commit the
	91	* current transaction and start a new one. We will then
	92	* need to call xfs_ialloc again to get the inode.
	93	*
	94	* If xfs_ialloc did an allocation to replenish the freelist,
	95	* it returns the bp containing the head of the freelist as
	96	* ialloc_context. We will hold a lock on it across the
	97	* transaction commit so that no other process can steal
	98	* the inode(s) that we've just allocated.
	99	*/
	100	code = xfs_ialloc(tp, dp, mode, nlink, rdev, credp, prid, okalloc,
	101	&ialloc_context, &call_again, &ip);
	102
	103	/*
	104	* Return an error if we were unable to allocate a new inode.
	105	* This should only happen if we run out of space on disk or
	106	* encounter a disk error.
	107	*/
	108	if (code) {
	109	*ipp = NULL;
	110	return code;
	111	}
	112	if (!call_again && (ip == NULL)) {
	113	*ipp = NULL;
	114	return XFS_ERROR(ENOSPC);
	115	}
	116
	117	/*
	118	* If call_again is set, then we were unable to get an
	119	* inode in one operation. We need to commit the current
	120	* transaction and call xfs_ialloc() again. It is guaranteed
	121	* to succeed the second time.
	122	*/
	123	if (call_again) {
	124
	125	/*
126	* Normally, xfs_trans_commit releases all the locks.
127	* We call bhold to hang on to the ialloc_context across
128	* the commit. Holding this buffer prevents any other
129	* processes from doing any allocations in this
130	* allocation group.
131	*/
132	xfs_trans_bhold(tp, ialloc_context);
133	/*
134	* Save the log reservation so we can use
135	* them in the next transaction.
136	*/
137	log_res = xfs_trans_get_log_res(tp);
138	log_count = xfs_trans_get_log_count(tp);
139
140	/*
141	* We want the quota changes to be associated with the next
142	* transaction, NOT this one. So, detach the dqinfo from this
143	* and attach it to the next transaction.
144	*/
145	dqinfo = NULL;
146	tflags = 0;
147	if (tp->t_dqinfo) {
148	dqinfo = (void *)tp->t_dqinfo;
149	tp->t_dqinfo = NULL;
150	tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
151	tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
152	}
153
154	ntp = xfs_trans_dup(tp);
1c72bf90	155	code = xfs_trans_commit(tp, 0);
1da177e4 LT	156	tp = ntp;
	157	if (committed != NULL) {
	158	*committed = 1;
	159	}
	160	/*
	161	* If we get an error during the commit processing,
	162	* release the buffer that is still held and return
	163	* to the caller.
	164	*/
	165	if (code) {
	166	xfs_buf_relse(ialloc_context);
	167	if (dqinfo) {
	168	tp->t_dqinfo = dqinfo;
7d095257	169	xfs_trans_free_dqinfo(tp);
1da177e4 LT	170	}
	171	*tpp = ntp;
	172	*ipp = NULL;
	173	return code;
	174	}
cc09c0dc DC	175
	176	/*
	177	* transaction commit worked ok so we can drop the extra ticket
	178	* reference that we gained in xfs_trans_dup()
	179	*/
	180	xfs_log_ticket_put(tp->t_ticket);
1da177e4 LT	181	code = xfs_trans_reserve(tp, 0, log_res, 0,
	182	XFS_TRANS_PERM_LOG_RES, log_count);
	183	/*
	184	* Re-attach the quota info that we detached from prev trx.
	185	*/
	186	if (dqinfo) {
	187	tp->t_dqinfo = dqinfo;
	188	tp->t_flags \|= tflags;
	189	}
	190
	191	if (code) {
	192	xfs_buf_relse(ialloc_context);
	193	*tpp = ntp;
	194	*ipp = NULL;
	195	return code;
	196	}
	197	xfs_trans_bjoin(tp, ialloc_context);
	198
	199	/*
	200	* Call ialloc again. Since we've locked out all
	201	* other allocations in this allocation group,
	202	* this call should always succeed.
	203	*/
	204	code = xfs_ialloc(tp, dp, mode, nlink, rdev, credp, prid,
	205	okalloc, &ialloc_context, &call_again, &ip);
	206
	207	/*
	208	* If we get an error at this point, return to the caller
	209	* so that the current transaction can be aborted.
	210	*/
	211	if (code) {
	212	*tpp = tp;
	213	*ipp = NULL;
	214	return code;
	215	}
	216	ASSERT ((!call_again) && (ip != NULL));
	217
	218	} else {
	219	if (committed != NULL) {
	220	*committed = 0;
	221	}
	222	}
	223
	224	*ipp = ip;
	225	*tpp = tp;
	226
	227	return 0;
	228	}
	229
	230	/*
	231	* Decrement the link count on an inode & log the change.
	232	* If this causes the link count to go to zero, initiate the
	233	* logging activity required to truncate a file.
	234	*/
	235	int /* error */
	236	xfs_droplink(
	237	xfs_trans_t *tp,
	238	xfs_inode_t *ip)
	239	{
	240	int error;
	241
	242	xfs_ichgtime(ip, XFS_ICHGTIME_CHG);
	243
	244	ASSERT (ip->i_d.di_nlink > 0);
245	ip->i_d.di_nlink--;
01651646	246	drop_nlink(VFS_I(ip));
1da177e4 LT	247	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
	248
	249	error = 0;
	250	if (ip->i_d.di_nlink == 0) {
	251	/*
	252	* We're dropping the last link to this file.
	253	* Move the on-disk inode to the AGI unlinked list.
	254	* From xfs_inactive() we will pull the inode from
	255	* the list and free it.
	256	*/
	257	error = xfs_iunlink(tp, ip);
	258	}
	259	return error;
	260	}
	261
	262	/*
	263	* This gets called when the inode's version needs to be changed from 1 to 2.
	264	* Currently this happens when the nlink field overflows the old 16-bit value
	265	* or when chproj is called to change the project for the first time.
	266	* As a side effect the superblock version will also get rev'd
	267	* to contain the NLINK bit.
	268	*/
	269	void
	270	xfs_bump_ino_vers2(
	271	xfs_trans_t *tp,
	272	xfs_inode_t *ip)
	273	{
	274	xfs_mount_t *mp;
1da177e4	275
579aa9ca	276	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
51ce16d5	277	ASSERT(ip->i_d.di_version == 1);
1da177e4	278
51ce16d5	279	ip->i_d.di_version = 2;
1da177e4 LT	280	ip->i_d.di_onlink = 0;
	281	memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
	282	mp = tp->t_mountp;
62118709	283	if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
3685c2a1	284	spin_lock(&mp->m_sb_lock);
62118709 ES	285	if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
62118709 ES	286	xfs_sb_version_addnlink(&mp->m_sb);
3685c2a1	287	spin_unlock(&mp->m_sb_lock);
1da177e4 LT	288	xfs_mod_sb(tp, XFS_SB_VERSIONNUM);
1da177e4 LT	289	} else {
3685c2a1	290	spin_unlock(&mp->m_sb_lock);
1da177e4 LT	291	}
	292	}
	293	/* Caller must log the inode */
	294	}
	295
	296	/*
	297	* Increment the link count on an inode & log the change.
	298	*/
	299	int
	300	xfs_bumplink(
	301	xfs_trans_t *tp,
	302	xfs_inode_t *ip)
	303	{
	304	if (ip->i_d.di_nlink >= XFS_MAXLINK)
	305	return XFS_ERROR(EMLINK);
	306	xfs_ichgtime(ip, XFS_ICHGTIME_CHG);
	307
	308	ASSERT(ip->i_d.di_nlink > 0);
	309	ip->i_d.di_nlink++;
01651646	310	inc_nlink(VFS_I(ip));
51ce16d5	311	if ((ip->i_d.di_version == 1) &&
1da177e4 LT	312	(ip->i_d.di_nlink > XFS_MAXLINK_1)) {
	313	/*
	314	* The inode has increased its number of links beyond
	315	* what can fit in an old format inode. It now needs
	316	* to be converted to a version 2 inode with a 32 bit
	317	* link count. If this is the first inode in the file
	318	* system to do this, then we need to bump the superblock
	319	* version number as well.
	320	*/
	321	xfs_bump_ino_vers2(tp, ip);
	322	}
	323
	324	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
	325	return 0;
	326	}
	327
	328	/*
	329	* Try to truncate the given file to 0 length. Currently called
	330	* only out of xfs_remove when it has to truncate a file to free
	331	* up space for the remove to proceed.
	332	*/
	333	int
	334	xfs_truncate_file(
	335	xfs_mount_t *mp,
	336	xfs_inode_t *ip)
	337	{
	338	xfs_trans_t *tp;
	339	int error;
	340
	341	#ifdef QUOTADEBUG
	342	/*
	343	* This is called to truncate the quotainodes too.
	344	*/
	345	if (XFS_IS_UQUOTA_ON(mp)) {
	346	if (ip->i_ino != mp->m_sb.sb_uquotino)
	347	ASSERT(ip->i_udquot);
	348	}
c8ad20ff	349	if (XFS_IS_OQUOTA_ON(mp)) {
1da177e4 LT	350	if (ip->i_ino != mp->m_sb.sb_gquotino)
	351	ASSERT(ip->i_gdquot);
	352	}
	353	#endif
	354	/*
	355	* Make the call to xfs_itruncate_start before starting the
	356	* transaction, because we cannot make the call while we're
	357	* in a transaction.
	358	*/
	359	xfs_ilock(ip, XFS_IOLOCK_EXCL);
d3cf2094 LM	360	error = xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, (xfs_fsize_t)0);
	361	if (error) {
	362	xfs_iunlock(ip, XFS_IOLOCK_EXCL);
	363	return error;
	364	}
1da177e4 LT	365
	366	tp = xfs_trans_alloc(mp, XFS_TRANS_TRUNCATE_FILE);
	367	if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
	368	XFS_TRANS_PERM_LOG_RES,
	369	XFS_ITRUNCATE_LOG_COUNT))) {
	370	xfs_trans_cancel(tp, 0);
	371	xfs_iunlock(ip, XFS_IOLOCK_EXCL);
	372	return error;
	373	}
	374
	375	/*
	376	* Follow the normal truncate locking protocol. Since we
9da096fd	377	* hold the inode in the transaction, we know that its number
1da177e4 LT	378	* of references will stay constant.
	379	*/
	380	xfs_ilock(ip, XFS_ILOCK_EXCL);
	381	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL \| XFS_IOLOCK_EXCL);
	382	xfs_trans_ihold(tp, ip);
	383	/*
	384	* Signal a sync xaction. The only case where that isn't
	385	* the case is if we're truncating an already unlinked file
	386	* on a wsync fs. In that case, we know the blocks can't
	387	* reappear in the file because the links to file are
	388	* permanently toast. Currently, we're always going to
	389	* want a sync transaction because this code is being
	390	* called from places where nlink is guaranteed to be 1
	391	* but I'm leaving the tests in to protect against future
	392	* changes -- rcc.
	393	*/
	394	error = xfs_itruncate_finish(&tp, ip, (xfs_fsize_t)0,
	395	XFS_DATA_FORK,
	396	((ip->i_d.di_nlink != 0 \|\|
	397	!(mp->m_flags & XFS_MOUNT_WSYNC))
	398	? 1 : 0));
	399	if (error) {
	400	xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES \|
	401	XFS_TRANS_ABORT);
	402	} else {
	403	xfs_ichgtime(ip, XFS_ICHGTIME_MOD \| XFS_ICHGTIME_CHG);
1c72bf90	404	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
1da177e4 LT	405	}
	406	xfs_iunlock(ip, XFS_ILOCK_EXCL \| XFS_IOLOCK_EXCL);
	407
	408	return error;
	409	}